From 28f36a3aef472d0fed3781fb795a6cd644a16f7f Mon Sep 17 00:00:00 2001
From: Reijo Keskitalo <reijo.keskitalo@gmail.com>
Date: Fri, 3 Jan 2020 15:16:25 -0800
Subject: [PATCH] High cadence scans (#316)

* Rewrite CES scanning simulation to support sinc-modulated scanning. FIX a bug in turnaround acceleration.

* Update data commit hash

* add command line options to enable sinc modulation
---
 src/toast/todmap/sim_tod.py | 38 +++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/src/toast/todmap/sim_tod.py b/src/toast/todmap/sim_tod.py
index dc716907c..cad3d766a 100644
--- a/src/toast/todmap/sim_tod.py
+++ b/src/toast/todmap/sim_tod.py
@@ -789,7 +789,11 @@ def __init__(
         hwprpm=None,
         hwpstep=None,
         hwpsteptime=None,
+<<<<<<< HEAD
         cosecant_modulation=False,
+=======
+        sinc_modulation=False,
+>>>>>>> High cadence scans (#316)
         **kwargs
     ):
         if samples < 1:
@@ -845,7 +849,11 @@ def __init__(
             raise RuntimeError("Unknown coordinate system: {}".format(coord))
         self._coord = coord
         self._report_timing = report_timing
+<<<<<<< HEAD
         self._cosecant_modulation = cosecant_modulation
+=======
+        self._sinc_modulation = sinc_modulation
+>>>>>>> High cadence scans (#316)
 
         self._observer = ephem.Observer()
         self._observer.lon = self._site_lon
@@ -1035,14 +1043,23 @@ def simulate_scan(self, samples):
         nstep = 10000
 
         azmin, azmax = [self._azmin, self._azmax]
+<<<<<<< HEAD
         if self._cosecant_modulation:
             # We always simulate a rising cosecant scan and then
+=======
+        if self._sinc_modulation:
+            # We always simulate a rising sinc scan and then
+>>>>>>> High cadence scans (#316)
             # mirror it if necessary
             azmin %= np.pi
             azmax %= np.pi
             if azmin > azmax:
                 raise RuntimeError(
+<<<<<<< HEAD
                     "Cannot scan across zero meridian with cosecant-modulated scan"
+=======
+                    "Cannot scan across zero meridian with sinc-modulated scan"
+>>>>>>> High cadence scans (#316)
                 )
         elif azmax < azmin:
             azmax += 2 * np.pi
@@ -1060,7 +1077,11 @@ def simulate_scan(self, samples):
         tvec = []
         azvec = []
         t0 = t
+<<<<<<< HEAD
         if self._cosecant_modulation:
+=======
+        if self._sinc_modulation:
+>>>>>>> High cadence scans (#316)
             t1 = t0 + (np.cos(azmin) - np.cos(azmax)) / base_rate
             tvec = np.linspace(t0, t1, nstep, endpoint=True)
             azvec = np.arccos(np.cos(azmin) + base_rate * t0 - base_rate * tvec)
@@ -1077,7 +1098,11 @@ def simulate_scan(self, samples):
         # turnaround
 
         t0 = t
+<<<<<<< HEAD
         if self._cosecant_modulation:
+=======
+        if self._sinc_modulation:
+>>>>>>> High cadence scans (#316)
             dazdt = base_rate / np.abs(np.sin(azmax))
         else:
             dazdt = base_rate
@@ -1096,7 +1121,11 @@ def simulate_scan(self, samples):
         tvec = []
         azvec = []
         t0 = t
+<<<<<<< HEAD
         if self._cosecant_modulation:
+=======
+        if self._sinc_modulation:
+>>>>>>> High cadence scans (#316)
             t1 = t0 + (np.cos(azmin) - np.cos(azmax)) / base_rate
             tvec = np.linspace(t0, t1, nstep, endpoint=True)
             azvec = np.arccos(np.cos(azmax) - base_rate * t0 + base_rate * tvec)
@@ -1113,7 +1142,11 @@ def simulate_scan(self, samples):
         # turnaround
 
         t0 = t
+<<<<<<< HEAD
         if self._cosecant_modulation:
+=======
+        if self._sinc_modulation:
+>>>>>>> High cadence scans (#316)
             dazdt = base_rate / np.abs(np.sin(azmin))
         else:
             dazdt = base_rate
@@ -1138,8 +1171,13 @@ def simulate_scan(self, samples):
         tmin, tmax = tvec[0], tvec[-1]
         tdelta = tmax - tmin
         self._az = np.interp((times - tmin) % tdelta, tvec - tmin, azvec)
+<<<<<<< HEAD
         if self._cosecant_modulation and self._azmin > np.pi:
             # We always simulate a rising cosecant scan and then
+=======
+        if self._sinc_modulation and self._azmin > np.pi:
+            # We always simulate a rising sinc scan and then
+>>>>>>> High cadence scans (#316)
             # mirror it if necessary
             self._az += np.pi
         ind = np.searchsorted(tvec - tmin, (times - tmin) % tdelta)